Are essential oils really effective against bedbugs?

Between 2017 and 2022, 11% of French homes were infested with bed bugs, a recent Ipsos survey for the National Agency for Health Security (ANSES) found. It is enough to cause a collective fear that we find ourselves colonized by these parasites one by one and no longer able to get rid of them. Home remedies to protect yourself abound on social media and in storefronts. Among the most popular are essential oils. Aspic lavender, tea tree, Java lemongrass, cloves… These powerful plant extracts pride themselves on their repellent, insecticidal, but also soothing properties against bites. What is it really?

Still ineffective for complete eradication

When Dr. Arezki Izri, an entomologist and parasitologist, is asked by the head of department at Avicen Hospital in Bobigny about the purported virtues of essential oils, the health worker is immediately skeptical. “To my knowledge, no scientific studies have investigated or confirmed the effectiveness of essential oils against bedbugs,” he reports. A few years ago, this specialist came to the same conclusion by looking at the interaction of these plant extracts with another parasite, the head louse, as part of a university thesis. “Of the 40,000 oils tested in the lab, none were effective against lice. “Regardless of the product, the parasite always penetrated and bit the skin,” he says.

Jean-Michel Berenger, an entomologist at IHU Méditerranée Infection in Marseille and co-founder of the National Institute for the Study and Control of Bed Bugs (INELP), agrees. “The deadly effect (a substance designed to kill harmful organisms, Editor’s Note) that product is being studied in laboratories, but currently none have provided conclusive evidence, unlike the chemical treatment used by professional disinfectants,” he explains. The specialist speaks with knowledge, as he grows about 15,000 stains in the laboratory to study their activity.

Among the promising ways, however, the entomologist mentions geranium essential oil, whose main molecule, geraniol, “kills the beetle instantly,” notes Jean-Michel Berenger. But there are several disadvantages of its use. “First, its very strong and overpowering smell can disturb people. In addition, this oil requires some caution when using and should be carefully diluted with a neutral vegetable base, such as sweet almond oil, to avoid the risk of allergenicity, explains the specialist. It should then be sprayed directly on each insect and not left to dry on a stand near the parasites. Which ultimately requires a huge amount of product and therefore increases its scent disadvantage.

Let’s remind that the use of essential oils is strictly prohibited for pregnant women and children under 6 years of age, and before using them, they should always be subject to medical advice, health experts say.

repellent properties should not be neglected

But the entomologist still admits the advantage of essential oils; These insects, like many others, have antennae that act like noses, which are very sensitive to strong smells, he says. “If you want to protect your suitcase or bag while traveling in an area you consider at risk of contamination, you can spray your luggage with a little scented essential oil to scare away bed bugs,” advises Jean-Michel Berenger.

Among the most disturbing odors for these insects, the entomologist mentions the odors of lavender and citriiodiol (which can also be found under the name PMD or essential oil of lemon eucalyptus). The specialist actually observed this phenomenon by placing the beds in a box, in which a very fragrant essential oil was sprayed. “The result was obvious. the bugs gathered on the side where there was no essential oil,” recalls Jean-Michel Berenger.

If you want to protect your suitcase or bag while traveling, you can spray your luggage with a little scented essential oil to scare away bed bugs.

Jean-Michel Berenger, entomologist at the IHU Méditerranée Infection in Marseille

To minimize the risk of allergens, the entomologist recommends choosing pre-diluted mixtures with a neutral herbal base. “There are mosquito repellent formulations that must be applied specifically to fabrics that contain these essential oils, and whose composition is strictly controlled before they are marketed,” he elaborates.

However, if you want to sprinkle it around your house, hold back. “The repellent does not kill the insect, but disturbs it, to the extent that it forces it to migrate from one place to another,” explains Dr. Arezki Izri. Instead, choose to use it as a preventative measure to check whether an item, suitcase, laundry room, or even a location, such as a hotel room, is contaminated. It can also be sprayed on your front door frame in case a neighbor is infested with bed bugs.

Lavender for mild itching

In case of contamination, the bite of a roach can cause itching and various allergic reactions in 70% of the population. In this situation, the same measures against mosquito bites are used, according to entomologist Jean-Michel Berenger. “In addition to having a strong repulsive smell, lavender essential oil contains anti-coagulant and soothing properties aimed at reducing inflammation associated with the bite,” explains the specialist.

In the event of an acute allergic reaction, burns or swelling, parasitologist Arezki Izri invites you to consult a healthcare practitioner, general practitioner or pharmacist, who can recommend an anti-inflammatory cream or antihistamine.